JPH09243748A - Range finding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To terminate a measurement data collecting operation for this once and determine the distance and direction in a short time by sampling and storing each output of a receiving means synchronously with a transmitting time in time series, and determining the distance and direction to a reflecting object from the received data in the stored sample timing. SOLUTION: An arithmetic processing part 10 has a logic circuit for outputting a transmission start signal (a) and starting a distance measuring operation. The processing part 10 outputs the transmission start signal (a) to a transmission part 11, and also imparts n+1 sampling clocks (b) in parallel to n+1 shift resistors 15a of a memory part 15. The distance and direction of an obstruction in a prescribed monitoring area are collected in the memory part 15 by one transmission start signal (a). The processing part 10 outputs address data to an address decoder 15b when the transmission of the clocks (b) is terminated, and reads the received data from the memory part 15 to detect the distance and direction. The collecting operation of information is terminated for this once. The number of detecting directions can be increased without enlarging the circuit scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the distance from the round trip time until the transmitted pulse-like measurement wave is reflected by an object and returns to the reflected object, and at the same time, can detect the presence direction. The present invention relates to a measuring device, and particularly to a distance measuring device suitable as a sensor for monitoring the path of a moving body.

[0002]

2. Description of the Related Art A distance measuring device mounted on a vehicle and used for monitoring the front, side, and rear of the vehicle is required to be able to measure the distance to an obstacle and at the same time detect the presence direction of the obstacle. It In this type of distance measuring device,
For example, a laser radar having the configuration shown in FIG. 3 is often used.

FIG. 3 is a block diagram of a conventional distance measuring device showing a simplified vehicle-mounted laser radar. The on-vehicle laser radar as the distance measuring device includes an arithmetic processing unit 31,
The transmitter 32, the receiver 33, the amplifier 34, and the signal selector 35 are provided. The arithmetic processing unit 31 controls an oscillator that gives a time reference, a logic circuit that outputs a transmission start signal a to the transmitting unit 32 in synchronization with the oscillator and starts a distance measurement operation, and controls them together and starts transmission. And a microcomputer that outputs a selection signal e to the signal selection unit 35 in synchronization with the output of the signal a, receives the reception signal f from the signal selection unit 35, and executes the distance calculation.

The transmitter 32 includes a laser diode, a drive circuit for pulse-exciting the laser diode by receiving the transmission start signal a from the arithmetic processing unit 31, and an optical system for collimating the output pulse light of the laser diode. . The receiving unit 33 is arranged so as to be able to separately receive reflected pulsed light from a predetermined region (hereinafter referred to as “monitoring region”) in front of the vehicle, which is irradiated with the pulsed light transmitted by the transmitting unit 32, according to the reflection position. A plurality of light receiving elements and an optical system that collects the reflected pulsed light on the light receiving surface of each light receiving element.

The plurality of light receiving elements are, for example, PIN photodiodes arrayed. Light receiving element P
The cathodes of the IN photodiodes are commonly connected to a power source, and the anodes of the IN photodiodes are the output terminals of the receiving unit 33. The amplification unit 34 includes a plurality of wide band amplifiers provided for each light receiving element of the reception unit 33. Each amplifier amplifies the output of the corresponding light receiving element to an appropriate level and outputs it to the signal selection unit 35.

The signal selection unit 35 receives the selection signal e from the arithmetic processing unit 31, and selects the circuit for selecting the designated amplifier of the amplification unit 34 and the magnitude relationship between the output level of the selected amplifier and the reference value. If the output level of the amplifier is compared with the reference value or more, “1” is provided, and if the output level of the amplifier is less than the reference value, “0” is provided as the received signal f to the arithmetic processing unit 31.

In the above configuration, the arithmetic processing section 31 is
The transmission start signal a is output to the transmission unit 32, and in synchronization therewith, the selection signal e for selecting the output of one amplifier of the amplification unit 34 is output to the signal selection unit 35. Transmitter 3
2 receives the transmission start signal a from the arithmetic processing unit 31,
A laser pulse light having a predetermined time width is sent toward a predetermined monitoring area in front of the vehicle. When an obstacle is present in the predetermined monitoring area, the reflected pulsed light at the obstacle is received by any one or a plurality of light receiving elements in the receiving unit 33, and the received signal is received by the corresponding amplifier of the amplifying unit 34. The signal is amplified to an appropriate level and input to the signal selection unit 35.

The signal selecting section 35 gives the output content ("1" level or "0" level) of one amplifier designated by the selection signal e from the arithmetic processing section 31 to the arithmetic processing section 31 as a reception signal f. . When the reception signal f input from the signal selection unit 35 is at “1” level, the arithmetic processing unit 31 has an obstacle, so that the reception signal f from the signal selection unit 35 is output from the time when the transmission start signal a is output. The time to the point of input is measured, and the distance to the obstacle is calculated from the measured time and the speed of light.

The received signal f input from the signal selector 35
Includes the direction information determined by the arrangement of the light receiving elements of the receiving unit 33, and therefore the arithmetic processing unit 31 simultaneously detects the direction in which the received signal f is acquired simultaneously with the distance measurement.
Since the arithmetic processing unit 31 can acquire the reception signal from one direction by one transmission, in order to acquire the reception signals f for all the receiving elements of the reception unit 33, the selection signal e to the signal selection unit 35 is acquired. It is necessary to repeatedly generate the transmission start signal a while changing the contents of the above, for the number of receiving elements of the receiving unit 33.

However, when the received signal f input from the signal selection section 35 is at "1" level, the reflected pulsed light from the vicinity of that direction may be targeted, so that the received signals for all the light receiving elements are not necessarily required. In some cases, it is not necessary to acquire f. Although the above is an example in which a plurality of light receiving elements are provided in the receiving section, one light receiving element is provided in the receiving section and a scanning mechanism is provided in front of the transmitting section and the receiving section so that the monitoring area can be scanned. There is also known a distance measuring device which is capable of obtaining sufficient measurement information about a monitoring area by one light receiving element.

In any case, the time T required for distance measurement by the conventional distance measuring device is T = (number of detection directions) × (distance measuring operation time) (1)

[0012]

By the way, the route sensor mounted on the vehicle is required to be able to accurately determine the situation in order to avoid a collision. For that purpose, the number of detection directions is increased and the measurement is performed. It is necessary to narrow the space between directions.

However, since the conventional distance measuring device is configured to perform measurement in each direction as described above, if the number of detection directions is increased for accurate situation determination,
As is clear from (1), the measurement time becomes longer as the number of detection directions increases.

That is, if the number of detection directions is simply increased by the conventional distance measuring device, it may take too much time to make an accurate situation determination, and it may be difficult to avoid collision. To shorten the time required for distance measurement,
In the conventional device, the arithmetic processing unit 31 may be provided for each detection direction, but this would increase the circuit scale and would be expensive.

The present invention was created in order to solve such a conventional problem, and it is possible to increase the number of detection directions without increasing the circuit scale and to increase the distance measurement time. It is an object of the present invention to provide a distance measuring device capable of measuring distance in a short time.

[0016]

According to a first aspect of the present invention, there is provided a transmitting means for transmitting a pulsed measuring wave, and a pulsed measuring wave transmitted by the transmitting means is reflected and returned from within a range of irradiation. In a distance measuring device having a receiving means for receiving the respective reflected pulse waves separately according to the reflection position, a signal detecting means for receiving respective outputs of the receiving means in parallel and binarizing them, and a signal detecting means Storage means for receiving the outputs in parallel and storing each reception data sampled in time series in synchronization with the transmission time of the transmission means, and the distance and direction from the reception data at the sample timing stored in the storage means to the reflecting object And a measuring means for determining

According to a second aspect of the present invention, in the distance measuring apparatus according to the first aspect, a connection for changing the correspondence between each output of the receiving means and each input to the storage means by changing the signal path. And a change content determining unit that determines the content of the change based on the received data when it is determined that the connection change unit should change the connection based on the received data stored in the storage unit. To do.

According to a third aspect of the present invention, in the distance measuring apparatus according to the first aspect, a connection for changing the correspondence between each output of the receiving means and each input to the storage means by changing the signal path. When it is determined that the changing means, the moving direction detecting means for detecting the moving direction of the moving body equipped with the device, and the connection changing means to change the connection based on the received data stored in the storing means, the change contents are displayed. Change content determining means for determining based on the output content of the moving direction detecting means.

(Operation) In the invention described in claim 1, the storage means stores each reception data obtained by sampling each output of the signal detection means in time series in synchronization with the transmission time of the transmission means, and the measurement means , The distance and direction from the received data at the sample timing stored in the storage means to the reflecting object are obtained.

The operation of storing each output of the signal detecting means, that is, each output of the receiving means in the storage means is a measurement information collecting operation. This measurement information collecting operation is performed by the transmitting means 1
It ends with the transmission operation of times. Therefore, the measuring means can obtain the distance and the direction within a short time. In the invention according to claim 2, when the change content determining means determines that the connection should be changed based on the received data stored in the storage means, the connection changing means and each of the receiving means according to the content of the received data. The correspondence between the output and each input of the storage means is changed. That is, the received data stored in the storage means is weighted by changing the connection.

Therefore, when the received data initially stored in the storage means indicates that there is an obstacle in the vicinity of the distance measuring device, it is determined from the storage means how important it is to the distance measuring device. It can be included in the received data to be read and output. In the invention according to claim 3, when the change content determining means determines that the connection should be changed based on the received data stored in the storage means, the connection changing means is instructed according to the moving direction indicated by the moving direction detecting means. , The correspondence between each output of the receiving means and each input of the storage means is changed. That is, the received data stored in the storage means is weighted by changing the connection.

Therefore, when the received data initially stored in the storage means indicates that there is an obstacle in the vicinity of the distance measuring device, the obstacle is avoided in the traveling direction of the moving body on which the device is mounted. It is possible to include in the received data read out from the storage means, for example, a measure required, and to output the received data.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a distance measuring device according to a first embodiment of the present invention. It is an embodiment for the invention described in claim 1. In FIG. 1, this distance measuring device includes an arithmetic processing unit 10, a transmission unit 11, a reception unit 12, an amplification unit 13, a signal detection unit 14, a storage unit 15, and the like. Similar to the arithmetic processing unit 31 shown in FIG. 3, the arithmetic processing unit 10 outputs the transmission start signal a to the transmitting unit 11 in synchronization with the oscillator that gives the time reference, and starts the distance measuring operation. Although a logic circuit and a microcomputer for controlling them are provided, the present invention is different from the conventional one in the configuration and function of the microcomputer.

That is, in the present invention, the microcomputer basically outputs the transmission start signal a only once, and in synchronization with the output of the transmission start signal a, n + 1 in the storage unit 15 is synchronized.
The sampling clock b is given to the individual shift registers 15a, and then the address decoder 15 of the storage unit 15 is provided.
The address data c is given to b, and the data selector 15c
The received data d is taken in from and the distance and direction are obtained.

Similar to the transmitter 32 shown in FIG. 3, the transmitter 11 includes a laser diode, a drive circuit for pulse-exciting the laser diode upon receiving a transmission start signal a from the arithmetic processing unit 10, and a laser diode. And an optical system for collimating the output light pulse.

The receiving unit 12 can separately receive the reflected pulsed light emitted from the predetermined region (hereinafter referred to as "monitoring region") in front of the vehicle, which is irradiated by the pulsed light transmitted by the transmitting unit 11, according to the reflection position. A plurality of light receiving elements arranged in
An optical system for collecting reflected pulsed light is provided on the light receiving surface of each light receiving element, and a plurality of light receiving elements can be configured by, for example, an array arrangement of PIN photodiodes, similar to the receiving unit 33 shown in FIG. However, in the present invention, the number of the plurality of light receiving elements is different from the conventional one.

That is, in the present invention, the plurality of light receiving elements are eight light receiving elements (# 0 to # in the example of FIG. 1) for convenience of explanation.
7) is shown arranged in a horizontal row, but basically any number can be provided. Specifically, depending on how much resolution is required, the light receiving elements are arranged, for example, two-dimensionally so that the reflected pulsed light from the entire predetermined monitoring area irradiated by the transmitted pulsed light does not leak. It is possible to provide as many as necessary to receive light. It can also be said that the configuration of FIG. 1 is part of a two-dimensional arrangement.

The amplifier 13 is similar to the amplifier 34 shown in FIG. 3 in that it comprises a plurality of wide band amplifiers provided for each light receiving element of the receiver 12. In the present invention, the output of each amplifier is given to the signal detection unit 14, respectively. The signal detection unit 14 includes a comparator that is provided for each amplifier of the amplification unit 13 and that can operate at high speed. The output of each comparator is applied in parallel to the data input terminal of the #n shift register 15a provided in the previous stage of the storage unit 15.

As described above, the storage unit 15 includes n + 1 shift registers 15a and an address decoder 15b.
And a data selector 15c. In the present embodiment, the n + 1 shift registers 15a are configured by cascade-connecting n + 1 shift registers each having the same number of bits as the number of light receiving elements (8 in the illustrated example) (that is, 8 bits).

The address decoder 15b and the data selector 15c operate to select the received data sampled and stored in the shift register 15a based on a command from the arithmetic processing unit 10 and give it to the arithmetic processing unit 10. Arithmetic processing unit 1
0 can handle the storage unit 15 as a read-only memory. The correspondence relationship between the configuration of the first embodiment and the invention according to claim 1 is as follows. Transmission unit 1
Reference numeral 1 corresponds to transmitting means, and the receiving unit 12 corresponds to receiving means. The signal detection unit 14 corresponds to a signal detection unit, and the storage unit 15 corresponds to a storage unit. In addition, the arithmetic processing unit 1
0 corresponds to the measuring means.

Next, the operation of the first embodiment configured as described above will be described with reference to FIG. In FIG. 1, the arithmetic processing unit 10 outputs the transmission start signal a to the transmission unit 11, and in synchronization with it, that is, at the same time or before and after the time, the arithmetic processing unit 10 stores the n + 1 shift registers 15a in the storage unit 15. The application of n + 1 sampling clocks b in parallel is started.

The transmission section 11 receives the transmission start signal a from the arithmetic processing section 10 and receives a laser pulse light of a predetermined time width (for example, 10 ns) (power is, for example, 10 to 3 at a peak value).
0W) is sent toward a predetermined monitoring area in front of the vehicle.
When an obstacle is present in the predetermined monitoring area, the reflected pulsed light from the obstacle is received by any one or a plurality of light receiving elements of the eight light receiving elements of the receiving section 12, and the received signal is amplified by the amplifying section. The signal is amplified to a suitable level by the corresponding amplifier 13 and input to the signal detector 14.

In the signal detecting section 14, each comparator compares the output level of the amplifier corresponding to the amplifying section 13 with the reference value, and if the output level of the amplifier is not less than the reference value, the output level is set to "1". If it is equal to or lower than the reference value, the output level is set to the “0” level. That is, the signal detection unit 14 binarizes each of the eight outputs of the reception unit 12 into either “1” or “0”, and parallelizes each of them to the shift register 15 a of the first stage #n of the storage unit 15. To the data input end of.

The level amplified by the amplifier 13 needs to be a level at which the signal detector 14 can properly determine whether the received signal level is "1" level or "0" level. Therefore, when a signal having a high reception level is mixed such as a reception signal from a short distance, the amplification degree of the amplification unit 13 and the reference value of the signal detection unit 14 may be changed with the passage of time. For the elapse of this time, for example, the time obtained from the sampling clock b can be used.

N + 1 shift registers 1 in the storage unit 15
5a receives the common sampling clock b and shifts in the connection direction, and the first-stage #n shift register 15a samples the parallel output of the signal detection unit 14 at the first sampling timing of the sampling clock b. The formed 8-bit received data is sequentially transferred in the connection direction and stored.

Therefore, the shift register 15 of the first stage #n
Received data by the pulsed light reflected at the farthest position is stored in a, and the shift register 15 of the final stage # 0 is stored.
The received data by the pulsed light reflected at the closest position is stored in a. That is, the arrangement position of the shift register 15a corresponds to the distance. The 8-bit received data of the shift register 15a includes direction information.

As described above, the storage unit 15 collects the information on the distance and the direction of the obstacle or the like in the predetermined monitoring area by one transmission start signal a. At that time, since the number of light receiving elements of the receiving unit 12 is increased,
It should be noted that the interval in the detection direction can be narrowed to collect detailed information. Then, the arithmetic processing unit 10
When the sending of the sampling clock b is completed, in order to detect the distance and the direction, the address data c is output to the address decoder 15b at an appropriate time thereafter, and the storage unit 1
The received data is read from 5. Note that this reading is performed, for example, first by the shift register 15 of the final stage # 0.
It is performed from the received data by the pulsed light reflected at the closest position stored in a.

In the storage section 15 which has received the address data c, the address decoder 15b decodes the inputted address data and gives a selection signal designating any one of the n + 1 shift registers 15a to the data selector 15c. In response to this, the data selector 15c takes in the received data that the designated shift register 15a outputs bit serially, and outputs it to the arithmetic processing unit 10 in bit parallel. Although not shown, the shift clock to each shift register 15a is supplied from the arithmetic processing unit 10.

The distance is obtained as follows. As described above, the arrangement position of the n + 1 shift registers 15a corresponds to each sample timing of the sampling clock and includes the distance information. Therefore, if the sample timing, that is, the arrangement position of the shift register 15a is referred to as “address”, The distance R indicated by the received data of a certain shift register 15a is R = (light speed) × (address) × (cycle of sampling clock) / 2 (2)

Further, the direction is obtained in relation to the arrangement position of the light receiving element. For example, the light receiving elements are arranged in a horizontal row as shown in FIG. 1, and the leftmost light receiving element # 0 is the data bit D0.
And the rightmost light receiving element # 7 corresponds to the data bit D7, it can be determined that the direction is the leftmost when the data bit D0 is "1". Further, according to the present invention, the size of the object can be approximately obtained by obtaining the direction information as the angle information. For example, when the angle per light receiving element to the right is assigned as θ with reference to the leftmost light receiving element # 0, a certain address m (0 <m <n)
Received data is D0 = 0, D1 = 1, D2 = 1, D3 = 1, D4
In the case of = 0, D5 = 0, D7 = 0, the distance of the object can be calculated by the equation (2), and the existence direction can be judged to be the direction of the angle θ from the leftmost end toward the center of 4 × θ, and its size is , (Tan (4 × θ) −tan (θ)) × distance ... (3)

In the above example, the data bit D1,
Regarding D2 and D3, it is necessary to confirm that the values from address m + 1 to address n are all "0". If even one "1" exists, it is possible that there is not only one object. The arithmetic processing unit 10 performs the above arithmetic processing on n + 1 received data,
Since it can be performed at high speed, the calculation time in this case does not matter so much. Therefore, not only can an appropriate situation be determined quickly for avoiding a collision, which was a problem in the conventional device, but also the information collecting operation can be completed once, so that appropriate measures can be taken promptly. Become.

Next, FIG. 2 is a block diagram of a distance measuring device according to a second embodiment of the present invention. It is an embodiment of the invention described in claims 2 and 3. In the second embodiment, the signal connection changing unit 21 is provided between the signal detecting unit 14 and the storage unit 15, and the moving direction detecting unit 22 is provided under the arithmetic processing unit 20 to move the device equipped with the present device. It is to judge the degree of danger such as how close the body is to the obstacle.

The signal connection changing unit 21 is a switch circuit that changes the correspondence relationship between each light receiving element output of the receiving unit 12 and each data input terminal of the shift register 15a of the storage unit 15 according to a command from the arithmetic processing unit 20. In FIG. 2, the switch circuit is configured by a logic circuit, but it is also possible to configure it by an analog switch. In that case, between the receiving unit 12 and the amplifying unit 13 or the amplifying unit 13 is possible. And the signal detection unit 14.

The moving direction detecting section 22 is a circuit which detects the moving direction of the moving body and reports it to the arithmetic processing section 20. In the second embodiment, for example, an acceleration sensor that detects lateral movement and a speedometer that detects movement speed are used. The arithmetic processing unit 20 also performs the operation of the connection content determining means described in claims 2 and 3 in addition to the operation of the arithmetic processing unit 10 of the first embodiment.

The correspondence relationship between the configuration of the second embodiment and the inventions according to claims 2 and 3 is as follows. The arithmetic processing unit 20 corresponds to the change content determining unit, the signal connection changing unit 21 corresponds to the connection changing unit, and the movement direction detecting unit 2
2 corresponds to the moving direction detecting means. Hereinafter, the risk determination operation performed in the second embodiment will be described. The arithmetic processing unit 20 makes a risk determination based on the content of the received data of the shift register 15a of the storage unit 15, and outputs a connection change command to the signal connection changing unit 21 when the risk is high. The content of the connection change command output to the connection change unit 21 is determined based on the traveling direction input from the movement direction detection unit 22.

The degree of danger increases as the distance to the obstacle is short and the distance is closer to the traveling direction.
When the light receiving elements # 3 and # 4 near the center of the are detecting obstacles (in this case, the data bits D3 and D4 of the received data are “1”), and are input from the moving direction detection unit 22. When the moving direction of the moving body is moving straight ahead, the degree of danger needs to be set high.

The determination of the degree of risk can be made by weighting the data bits of the received data of the shift register 15a. This weighting may be performed by software in the arithmetic processing unit 20 that takes in the received data, but in the present embodiment, the signal connection changing unit 21 is provided so that it can be quickly performed by the hardware.

Specifically, it is defined that the received data stored in the shift register 15a has a higher degree of danger as the higher order bits are, and the arithmetic processing unit 20 is in the danger direction as described above. When the light receiving element can be determined, the storage unit 15 and the signal detecting unit 1 are arranged so that the output of the light receiving element in the dangerous direction enters the most significant bit side of the shift register 15a.
The connection with 4 is changed. This is equivalent to weighting and is hardware processing, and therefore has an advantage that processing time can be shortened.

For example, as described above, the arithmetic processing unit 20 is dangerous from the traveling direction of the moving body input from the moving direction detecting unit 22 when the data bits D3 and D4 of the received data are "1". When it is determined that the outputs of the corresponding two light receiving elements # 3 and # 4 near the center of the receiving unit 12 are
It outputs a connection change command to the signal connection change unit 21 so as to enter the most significant bit and the next upper bit of the shift register 15a.

If the value of the 8-bit received data is, for example, "C0H" or more in hexadecimal notation, it is possible to simplify the determination sequence by determining that it is dangerous. In addition, in the risk determination including the distance, the shift register 15
The shift register 1 after changing the address and signal connection of a
By comparing the product or sum of the received data of 5a and the predetermined value of the risk level, it is possible to obtain the judgment data as to whether or not the vehicle is at the stopping distance.

Further, the sum of products and sums of the address of the shift register 15a and the received data of the shift register 15a after the signal connection is changed can be used as a criterion for judging the degree of danger in the entire traveling direction, which is useful in traffic jams and the like. It becomes a standard. Needless to say, in order to appropriately perform the above risk determination, it is necessary to send pulsed light from the transmitter 11 multiple times to collect distance information, but as described above, the problem ends because it is completed in a short time. Does not happen.

As is apparent from the above description, even if the moving direction detecting means 22 is omitted and the contents of the changed connection are determined from the contents of the received data, the direction information itself is included, and Since the moving body itself has a speedometer, almost the same functions can be realized. Since this embodiment is intended for use as a vehicle-mounted path sensor, high-speed operation is required. Therefore, although the receiving unit 12 is composed of a PIN photodiode array, it is assumed that the charge storage element can be naturally used in applications where the required speed is not so high by simple distance and direction detection other than the vehicle-mounted path sensor. To be done.

Further, although the shift register is used in the storage section 15, if it is desired to perform a high-speed operation of about 150 MHz, it may be better to use a D-type flip-flop or an ECL element. On the other hand, for applications in which the required speed is not so high, the method of updating and storing the RAM address may be used. Since the storage unit 15 can be integrated, even if the number of sampling clocks is increased to several hundreds of meters, the circuit scale does not increase so much, and the device can be downsized.

[0055]

As described above, according to the first aspect of the present invention, each output of the receiving means is sampled and stored in time series in synchronization with the transmission time, and the received data at the stored sample timing is stored. Since the distance and direction to the reflecting object are obtained, the measurement information collecting operation is completed once, and the distance and direction can be obtained within a short time.

That is, according to the first aspect of the present invention, a plurality of outputs of the receiving means can be stored at one time, and the measurement information collecting operation is completed in a short time. As a result, the number of outputs of the receiving means, that is, The number of detection directions can be significantly increased. In principle, the number of reflected waves that are reflected and returned from within the range irradiated by the pulsed measurement wave transmitted by the transmission means can be set to a number that can be received without leakage.

Therefore, when the distance measuring device is mounted on a moving body and used as a path sensor, it is possible to finely obtain the measurement information necessary for avoiding a danger, and in combination with the short measurement time, it is possible to judge an appropriate situation. Can be done quickly. According to the second aspect of the present invention, the correspondence between each output of the receiving means and the input of the storing means is changed based on the received data initially stored in the storing means, and the received data is weighted. If the received data indicates that an obstacle is present near the distance measuring device,
How important it is can be included in the received data read from the storage means and output.

According to the third aspect of the present invention, the correspondence between each output of the receiving means and the input of the storage means is changed according to the traveling direction of the moving body mounting the apparatus, and the received data is weighted. If the received data initially stored in the storage means indicates that there is an obstacle in the vicinity of the distance measuring device, the obstacle exists in the traveling direction of the moving body on which the device is mounted, and avoidance measures are required. It can be included in the received data read from the storage means and output.

That is, according to the second or third aspect of the invention, when the distance measuring device is mounted on a moving body and is used as a path sensor, it is possible to determine the situation in the vicinity of the moving body and perform risk avoidance measures. Can be picked quickly and appropriately. Further, since the storage means can be sufficiently miniaturized by making it into an integrated circuit, according to the present invention, the number of detection directions can be increased without increasing the circuit scale, and further, the distance measurement time is not increased. Therefore, it is possible to provide a small and inexpensive distance measuring device capable of measuring distance in a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a distance measuring device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a distance measuring device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional distance measuring device.

[Explanation of symbols]

 10, 20 arithmetic processing unit 11 transmitting unit 12 receiving unit 13 amplifying unit 14 signal detecting unit 15 storage unit 15a shift register 15b address decoder 15c data selector 21 signal connection changing unit 22 moving direction detecting unit

Claims (3)

[Claims] 1. A transmission means for transmitting a pulsed measurement wave, and a reflected pulse wave reflected and returned from within a range irradiated by the pulsed measurement wave transmitted by the transmission means according to each reflection position. In a distance measuring device including receiving means for receiving separately, a signal detecting means for receiving each output of the receiving means in parallel and binarizing the same, and receiving each output of the signal detecting means in parallel for the transmission. Storage means for storing each reception data sampled in time series in synchronization with the transmission time of the means, and measurement means for obtaining the distance and direction from the reception data at the sample timing stored in the storage means to the reflecting object. A distance measuring device characterized in that 2. The distance measuring device according to claim 1, wherein a connection changing unit that realizes a change in a correspondence relationship between each output of the receiving unit and each input to the storage unit by changing a signal path, When it is determined that the connection changing unit should change the connection based on the received data stored in the storage unit, the distance measurement is provided with a change content determining unit that determines the content of the change based on the received data. apparatus. 3. The distance measuring device according to claim 1, further comprising a connection changing unit that changes a correspondence relationship between each output of the receiving unit and each input to the storage unit by changing a signal path. When it is determined that the connection changing means should change the connection based on the received data stored in the storage means, the moving direction detecting means for detecting the moving direction of the moving body equipped with the device, A distance measuring device, comprising: a change content determining unit that determines the output content of the detecting unit.